Sen. Bob Corker and President Donald Trump have exchanged insults over the last few days. (CNN Newsource)

WASHINGTON (Sinclair Broadcast Group) —

White House Press Secretary Sarah Huckabee Sanders defended President Donald Trump’s Twitter tirades against a prominent member of his own party Tuesday, but experts say the infighting could endanger Republicans’ lagging legislative agenda.

“I don’t think he’s alienating anyone,” Sanders said at a press briefing. “I think that Congress has alienated themselves by not actually getting the job done that the people elected them to do.”

She also echoed President Trump’s criticism of Sen. Bob Corker, R-Tenn., chairman of the Senate Foreign Relations Committee.

“The Failing @nytimes set Liddle' Bob Corker up by recording his conversation. Was made to sound a fool, and that's what I am dealing with!” Trump wrote on Tuesday morning.

As the New York Times reporter who interviewed Corker observed, the senator was fully aware the interview was being recorded, but Trump’s apparent insult to his intelligence and height followed a weekend of increasingly volatile public comments from both men.

Last week, Corker suggested Chief of Staff John Kelly, Secretary of State Rex Tillerson, and Secretary of Defense James Mattis "help separate our country from chaos," an apparent reference to their ability to rein in the president.

Trump lashed out on Sunday morning, saying Corker “didn’t have the guts” to run for reelection and blaming him for the Iran nuclear deal. Corker tweeted in response that Trump has turned the White House into “an adult day care center.”

“I know for a fact that every single day at the White House it’s a situation of trying to contain him,” Corker said.

He insisted that he wants to see Trump succeed and has tried to work with him, but the president’s behavior is “to a degree, alarming.” He also dismissed the notion that Trump’s public disputes with his own Cabinet members are an intentional “good cop/bad cop” act.

“Sometimes I feel like he’s on a reality show of some kind, you know, when he’s talking about these big foreign policy issues,” Corker said. “And, you know, he doesn’t realize that, you know, that we could be heading towards World War III with the kinds of comments that he’s making.”

Republican strategist Ford O’Connell cautioned that Corker’s decision to take his concerns about the president public hinders Republicans’ ability to advance tax reform and other key agenda items, and in the long run, it could even cost them their slim Senate majority.

“I think Sen. Corker’s decision to go all ‘Bulworth’ on President Trump was highly irresponsible…,” O’Connell said. “I don’t think that Corker hurt Trump in any way. All Corker did is put his Senate GOP colleagues in a tough spot with the media.”

Other Republicans have attempted to stay out of the line of fire, even though Corker and many Capitol Hill reporters say some have expressed similar concerns about the president privately.

“Oh yeah,” Corker said when asked if his colleagues feel the same way. “Are you kidding me? Oh yeah.”

He acknowledged, however, that his decision not to run for reelection frees him to speak candidly and others may not have that luxury, particularly if they are facing conservative challengers in primaries.

“To be constrained by looking over your shoulder with some winger running against you, you know, let’s face it, that impedes your ability to serve,” he said.

As Glenn Altschuler, Litwin Professor of American Studies at Cornell University, put it, “Right now, all Republican officeholders with virtually no exceptions are hostage to the president.”

“There’s very little in it politically to break with the president because if they break with the president, they are not going to get support from Democratic voters,” he said. “So they’ll lose some Republican voters and gain almost nothing.”

He pointed to the example of Sen. Lindsey Graham, R-S.C., who once equated supporting Trump to being shot or poisoned but played a friendly round of golf with the president Monday and lauded his skills on Twitter afterward. Despite his acrimonious personal history with Trump—the two traded insults as recently as August—the president enthusiastically embraced Graham’s proposed Obamacare replacement bill last month.

The mending of that relationship points to a basic political truth that may mitigate the damage of the Corker feud: on most issues, Trump and congressional Republicans want the same things and they have to work together to get them.

“Whether you like Trump or not, it’s not like you’re going to get any of this done with the other side in power,” O’Connell said.

Especially on an issue like tax reform, it makes little sense to fight a Republican plan just because of who will be signing the final bill at the White House.

“I don’t think Republicans really support Trump’s agenda; I think he supports theirs on taxes and health care,” said David Barker, director of the Center for Congressional and Presidential Studies at American University. “They are going to paddle the same direction when their goals align.”

What will be more telling is what establishment Republicans do when those goals do not align or they have little invested in the outcome, like infrastructure or a border wall, and how they handle eventual confrontations over the investigation of Russian interference in the election.

Corker joins a short list of outspoken Republican senators who are willing to defy Trump, and with a two-seat majority in the Senate, his vote carries a lot of weight. He has waffled on tax reform because he opposes cuts that increase the deficit, but he seems unlikely to sink other legislation.

“I don’t know that it makes that much of a difference because Corker is still a conservative and he will vote for conservative bills if he thinks they are good,” Barker said.

Corker anticipated the firestorm his remarks would ignite when he spoke to the Times Sunday.

“We know that we will have some tough times, but it was the right thing to do,” he said.

Although he endorsed Trump during the presidential campaign and was reportedly under consideration to be Trump’s vice president and secretary of state, Corker has spoken out against him before. After Trump’s divisive response to violent protests in Charlottesville in August, he said the president “has not yet been able to demonstrate the stability nor some of the competence that he needs to demonstrate in order to be successful.”

“The importance of this [latest] exchange depends a lot on whether other Republicans decide that it’s now appropriate and maybe even necessary for them to speak out as well,” Altschuler said, “and at the moment there is no indication that Republicans either in the Senate or even more so in the House are likely to do so.”

As long as Republicans are fighting among themselves, Democratic strategist Craig Varoga said the best thing his party can do is stay out of the way and stay united.

“The only way Republicans can win is if Democrats fall into their own political civil war, which is possible but not certain,” he said. “With Trump continuing to attack D.C. Republicans, the likelihood of anything happening in Congress is somewhere between remote and zero.”

The dust-up with Corker comes as former White House Strategist Steve Bannon gears up for what Varoga described as “a self-destructive civil war” with the Republican establishment on Trump’s behalf for control of the Senate.

“We are declaring war on the Republican establishment that does not back the agenda that Donald Trump ran on and the president of the United States,” Bannon told Sean Hannity on Fox News Monday.

According to CNN, Bannon’s goal is to unseat Sen. Mitch McConnell, R-Ky., as majority leader and install Trump supporters who would back a vote to eliminate the legislative filibuster. He is reportedly meeting with top Republican donors and scouting potential candidates.

“Just voting is not good enough,” Bannon warned incumbents whose support for Trump is insufficiently enthusiastic on “Hannity.” “You have to have a sense of urgency. Nobody’s safe. We are coming after all of them and we are going to win.”

Bannon’s preferred candidate Roy Moore defeated the McConnell-backed Sen. Luther Strange in a primary in Alabama last month, but Barker is skeptical he can repeat that success elsewhere.

“Most regular folks have no idea who Steve Bannon is,” he said. “He doesn’t sway votes. Roy Moore won for reasons that had absolutely nothing to do with Bannon.”

Those who are in real danger in 2018, like Sens. Dean Heller, R-Nev., and Jeff Flake, R-Ariz., were already struggling to stay afloat without a Bannon-approved challenger.

Other incumbents may find supporting Trump is the path of least resistance, but while Trump’s base remains enthusiastic and vocal, new polls indicate his standing among the general public and even more moderate Republicans is slipping.

A Bannon-funded Trump supporter who embraces those increasingly-unpopular policies may play well with Alabama Republicans—and even there, Moore’s history of controversial comments has energized Democrats—but similar candidates dragging the party to the right in more moderate states could cost the GOP control of the Senate.

“If Jeff Flake is replaced by a Democrat, if Dean Heller is replaced by a Democrat, then pushing out the so-called establishment Republicans…the strategy obviously is a failure,” Altschuler said.

For Bannon, success in several key races could usher in a new generation of Trump-inspired Republican leaders, but experts say that potential reward comes with enormous risks.

“If Bannon doesn’t do this properly, everyone’s going to go home a loser,” O’Connell said. “You conceivably could have two Democrat senators in Arizona. How does that better serve the party?”